Heating sock



FIG. 1 is a perspective view of a heating sock showing the claimed design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a front elevation view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a rear elevation view thereof; and,

FIG. 7 is a bottom plan view thereof. 

CLAIM I claim the ornamental design for a heating sock, as shown and described. 